The two components of the title heterodimer, C17H21NO2·C8H5NO2, are linked end-to-end via O—H⋯O(=C) and C—H⋯O(=C) hydrogen-bond interactions. Additional lateral C—H⋯O interactions link the dimers in a side-by-side fashion to produce wide infinite molecular ribbons. Adjacent ribbons are interconnected via π–π stacking and C—H⋯π(arene) interactions. This structure represents the first evidence of robust hydrogen-bond formation between the moieties of pyridin-4(1H)-one and benzoic acid.
The forced oscillation technique (FOT) can provide unique and clinically relevant lung function information with little cooperation with subjects. However, FOT has higher variability than spirometry, possibly because strategies for quality control and reducing artifacts in FOT measurements have yet to be standardized or validated. Many quality control procedures rely on either simple statistical filters or subjective evaluation by a human operator. In this study, we propose an automated artifact removal approach based on the resistance against flow profile, applied to complete breaths. We report results obtained from data recorded from children and adults, with and without asthma. Our proposed method has 76% agreement with a human operator for the adult data set and 79% for the pediatric data set. Furthermore, we assessed the variability of respiratory resistance measured by FOT using within-session variation (wCV) and between-session variation (bCV). In the asthmatic adults test data set, our method was again similar to that of the manual operator for wCV (6.5 vs. 6.9%) and significantly improved bCV (8.2 vs. 8.9%). Our combined automated breath removal approach based on advanced feature extraction offers better or equivalent quality control of FOT measurements compared with an expert operator and computationally more intensive methods in terms of accuracy and reducing intrasubject variability.NEW & NOTEWORTHY The forced oscillation technique (FOT) is gaining wider acceptance for clinical testing; however, strategies for quality control are still highly variable and require a high level of subjectivity. We propose an automated, complete breath approach for removal of respiratory artifacts from FOT measurements, using feature extraction and an interquartile range filter. Our approach offers better or equivalent performance compared with an expert operator, in terms of accuracy and reducing intrasubject variability.
Plethysmographic specific airways resistance (s R aw) has remained the most recognised measure of airway resistance for almost 60 years [1]. Studies in both adults and children (including preschoolers) suggest clinical utility across important obstructive lung diseases [2–5]. Measurement protocols based on rapid panting or tidal breathing exist, and are incorporated into many current commercial plethysmographs. Tidal breathing measurement offers feasibility across a wide age range, and a relatively stable index with which to distinguish effects of disease from those of growth and development [6]. Both adult and paediatric reference data exists [7, 8]; however, the wide variation in methodology existing between centres has recently been highlighted [8], and s R aw remains one of the few lung function measurements without formal standardisation guidelines [9]. Despite the wide availability of plethysmographic equipment in lung function laboratories, its use is frequently confined to lung volume measurements. Although simultaneous measures of airway resistance can easily be recorded at no extra cost, the clinical applications of s R aw remain unclear. As part of ongoing s R aw standardisation work, we sought to describe current international use of s R aw across paediatric and adult respiratory laboratories. s R aw is widely used but results should be interpreted with caution until its recording is better standardised
Lung clearance index (LCI) is the most used outcome from the multiple-breath washout test. As known for decades, the LCI is not linearly related to dead space ventilation, giving difficulties interpreting changes over time and in clinical trials. We present a new and improved outcome based on LCI, the ventilation distribution efficiency (VDE), which solves this problem by being linearly related to dead space ventilation. A pediatric age range reference equation for VDE is presented.
While some training studies have identified that
walking increases strength and reduces functional
limitations in older adults, others have identified that
aerobic physical activity is ineffective in preventing
loss of muscle strength associated with ageing
(Harridge et al., 1997: Aging, 9, 80 – 87). As muscle
weakness in the legs has been found to be predictive
of falls, this would appear to be problematic for
aerobic-based physical activity recommendations for
the prevention of falls.
The purpose of this study was to identify whether
‘‘fallers’’ and ‘‘non-fallers’’ demonstrated significantly
different levels of attainment of the current
physical activity recommendations over the life
course. Self-report lifetime physical activity was
obtained through estimation of how many days per
week an individual accumulated 30 min or more of
at least moderate-intensity physical activity during
each decade of their adult life. A fall was identified as
a loss of balance resulting in the body, or part of the
body, coming to rest on the ground. Ethical approval
was granted through institutional procedures undertaken
at departmental level.
The participants were 74 males (mean age 71.7
years, s¼7.4) and 228 females (mean age 71.0 years,
s¼7.5; range 54 – 94) with 72% indicating that they
had experienced a fall. Differences between the sexes
were apparent for the number of days active in their
thirties (females: mean 6.41 days, s¼1.98; males:
mean 5.73 days, s¼2.01 days; t308¼2.56,
P50.05). Independent samples t-tests showed that
while ‘fallers’ (mean 4.75 days, s¼2.15) were
currently less active than ‘‘non-fallers’’ (mean 5.43
days, s¼2.03; t305¼2.52, P50.05), there was no
significant difference in the number of days on which
they had performed 30 min or more of moderateintensity
physical activity in any of the decades throughout the life-span. When participants were
then classified as either active or inactive in relation
to achieving 5630 min per week, chi-square tests
revealed no differences in proportional attainment of
the recommended amounts of physical activity in
fallers and non-fallers in any decade.
Although demonstrating a progressive decline in
physical activity through the decades, the sample was
more active than the current population in each
decade, with the majority attaining recommended
amounts of physical activity into their seventies.
Attainment of current physical activity guidelines
throughout the life-span would not appear to reduce
the likelihood of falling and would suggest that
strength-based physical activity recommendations
may be needed in addition to the current general
health guidelines if the number of falls in older adults
is to be significantly reduced.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRegioselective synthesis of substituted 1-thiohex-2-enopyranosidesLois V. Dunkerton, Nancy K. Adair, Jack M. Euske, Kevin T. Brady, and Paul D. RobinsonCite this: J. Org. Chem. 1988, 53, 4, 845–850Publication Date (Print):February 1, 1988Publication History Published online1 May 2002Published inissue 1 February 1988https://pubs.acs.org/doi/10.1021/jo00239a030https://doi.org/10.1021/jo00239a030research-articleACS PublicationsRequest reuse permissionsArticle Views311Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
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